convert to subTest

Author: arunkannawadi

tests/test_coadds.py

@@ -615,8 +615,9 @@ def test_coaddInputs(self):
         for position, _ in self.test_positions:
             ccds = inputs.subset_containing_ccds(position, None)
             visits = inputs.subset_containing_visits(position, None)
-            self.assertEqual(len(ccds), 1)
-            self.assertEqual(len(visits), 1)
+            with self.subTest(position=position):
+                self.assertEqual(len(ccds), 1)
+                self.assertEqual(len(visits), 1)
 
     def test_borders(self):
         """Test that the borders are populated correctly on stitching."""